Dueling target indicator



vJune 5, 1956 D. F. REAM 2,749,124

DUELING TARGET INDICATOR Filed April 6, 1955 VII'IIA I mums. a...

ATTORNEY United States Patent 2,749,124 DUELING TARGET mama Donald F. Ream, wasiiin 'ma, n. c. Application 6, 19 3 Serial No. $4 6,944 18 class (C1. z'l's-itizlzy This invention relatesto a target indicating pparatus hasparticular utility in dueling courses of fire. for indicating which ones of a plurality of targets have been struek and which one of said targets was struck first.

lnthe typeof target practiceknown as dueling, a number of contestantsare involved, there being a separate target foreach contestant. Upon receipt of the signal to fire, each contestantmust draw, aim and fire at his specified target as quickly as possible, the winner of the contest being the one who hits his specified target first. Asthe proficiency of the contestants increases, the difference between them in time taken to draw, aim and fire becomesless and less, with a consequent increase in the difiiculty of ascertaining whichone of the targets was struck first. To obviatethis difficulty, I haveinvented a dueling target indicator which is: thesubject of my United States patentapplication Serial No, 316,965, of which this applicationis a continuation-impart,

I Hereto fore, ithas been the practice to en1ploy, in some instances, mechanical means for determining which target wasstruck first. 'Ihe inaccuracies of such means stem from the time lags inherentin any mechanical system and, in addition, in most mechanical systems, the judgment of the referee in determining which target actuated its mechanical system first. I Qther indicating systemshave been evolved which involve the use of individual lights or buzzers for each target, the light being i r tu d on 0;. fi9tab us oun dwhe get is struck. I Sucha system while'usually fasteracting than t Ih BiPa ty s s.. ?a a lil n c ra e b cause of the. time lag the filaments of the l amp or the inertia of t'he buzzer striker and, usually, the, judgment of the referee. I Still other, indicating systems have been evolved whichr' d liss t pasystsm a te in Wh c 't t i. m9 n. d t n 1 wh h. t r e was ws fi H s rri'n. dd q lQ s af r men o objections, another objection rmsrman system is based upon the fact that the two indicating systems are in no way interrelated, with the consequence thatsuch systems are diflicu'lt to calibrate and maintain in proper Working order. I I I I I I In practically all duelingtargiet indicator systems, there isthe basic problem created by thetargets being located at a. considerable distance frorn the contestants and the referee, with the consequcntdifficulty of transmitting the indication from the target s to the referee. II ,I

It is an object of this invention to provide adueling taifgt indic ator capable of givingan exceedingly accurate indication of when a specific target has been struck.

It is ,a furth er object of this invention to proyidea target indicating apparatus which completely eliminates the element of human judgment in determining which one of a number of targets wasstruck first.

nother object of th invention is'to, provide a dueling target indicator system capable of indicating which of a plurality of targets" have been struck during a single course or fire.

s'tnr another objet 6f this initiation is to nova-s a I 2,749,124 b i atertted June 5,1956

ICE

2 dueling target indicator, the indicator portions of which may be located at any reasonable distance from thelta'rget without impairing the accutacy or operation of the system.-.

Still another object of this invention is to. provide a dueling target indicator requiringlittle maintenance .or adjustment after its initial calibration, andawhich is not affected by wide variationsin weatherconditions. Still further objects and advantages ofv thisinvent'iofi will be readily apparent from the following specification taken in conjunction with the drawings in which:.

Fig l is ,a schematic wiring diagram 0f a dueling'ta'r get, indicator embodying thepresent invention; and

lfig, 2 is a schematic Wiring diagramof another embodiment of the present invention in a dueling target iiidicator.

v In accomplishing the objects ofthis invention, Lfirovide a target indicating system, having a plurality of tar gets, usually two, and a control and indicatingelement capable of being placed at a location remote from the targets. Any once)? a number of various types of targets capable of giving an electricalindication or when they. have been struck may be used; for purposes of. ill'ustration, I have shown a targetof the. general type shown and described in U S. vPatent No. 474,109, which is of the type having two conductive plates separated by' a dielectric.

I Such typetarget usually consists of. two electrical conductive plates or screens separated bydielectric material of a thickness somewhat less than the length of the bullet or projectileused in target practice. A voltage islimpressed across the plates of .the target so, that the target acts as a large condenser. When the targetis pierced by a bullet, thev two plates will be momentarilyshort cir; cuited bythe bullet andthe charge on theplateswill be dissipated thereby creating a high frequency discharge pulse. Y If the target is located any substantial distance f r mthe indicator portion of thesystem, or if -th'e',,connections between the two involve any great'length of connecting Wire, this highfrequency discharge pulse will be rapidly attenuated and will be of little or no use in afiording an indication I A fter the plates; are discharged,. they will start to charge again as soon as the short circuit is removed,(i.. e., the bullet leaves the target), resulting in a, chargingtransient pulse of a much lower frequency andconsequen'tly longer time base than the discharge transient pulse. This charging pulse, being of a much lower fre'quency than the discharge pulse, will not be attenuated to any; great degree in the connecting cables between. the targets and the indicating circuit, as would the discharge pulse. By placing the prirnary of a transformer in series between one plate of each target and a power supply, it is possible to obtain alarge positive voltage pulse in the secondary of the transformer due to the chargingpulse in the primary. I his large positive voltage pulse is then used in the remainingportion of the indicator circuit to initiate the discharge of a gas-filled tube, thereby initiating the action of the indicator circuit. V s

This gas-filled tube, upon discharge, afi'ords an indication of when its associated targethas been struck In order to determine which of the targets was struck first, there is provided a second stage to the indicator circuit, comprising a gas-filled tube which is connected in circuit with the first gas-filled tube in such a manner as to be actuated by the discharge current of the first gas-filled tube. Eachof the gas-filled tubes of the sec: ond stages of the indicator circuits associated with the plurality oftargets is supplied with a D. C, bias from a power supply source which is not enough, however; to actuate the tube. However, the flow of current the gas-fined tube of the first indicator circuit will cause a change in the bias on the second gas-filled tube to cause it to ignite. When a plurality of targets have been struck but one of the targets was struck slightly in advance of the others, the ignition of the first gas-filled tube associated with that target will in turn ignite the second gas'filled tube associated therewith. The second gas-filled tubes associated with each of the targets are connected together in such a manner that when one of these tubes has been ignited, it will negatively bias the other tubes of the second stages, thereby preventing their ignition. Thus, the second gas-filled tube of the target which was struck first will be the only one which is ignited, thereby affording an indication of which of said targets was struck first.

In the embodiment here shown, I use the gas-filled tube itself which glows intensely when ignited to afford a visual indication of when its associated target has been struck, or when the associated target was struck first, although it is to be understood that any suitable indicating means may be used.

The action of the gas-filled tubes is so rapid that my indicating circuit will accurately indicate which target is struck first even though a subsequent hit may be made on one of the other targets less than one-tenth millisecond later, and at the same time my indicating circuit will indicate which targets have been struck.

Turning now to the drawings, and more particularly to Fig. l, I show an embodiment utilizing two identical targets and 11, target 10 having two electrodes of electrical conducting material 12 and 14, separated by a suitable dielectric material 16. In a like manner, target 11 has electrodes 13 and 15, separated by dielectric 17. In order to supply a D. C. potential difference to the plates of the targets, any suitable D. C. source may be used. In the embodiment, I use a standard dry cell battery 18 of approximately 90 volts, the terminals of which are connected to a voltage divider network comprising resistors 19, 20 and 21. A portion of the voltage across the divider is fed through lead 22 to terminal 23. One end of the primary 24 of a transformer T2 and one end of the primary 25 of a transformer T1 are likewise connected to terminal 23. The other end of the primary 24 is connected to a terminal 26, and the other end of primary 25 is connected to a terminal 27. The negative side of battery 18 is connected through lead 28 to ground and thence to terminals 29 and 30 of the target circuit. Terminals 26 and 30 are connected to terminals 32 and 34 by means of cable 36 which may be any standard cable, such as a twisted pair or the like. In a like manner, terminals 27 and 29 are connected respectively to terminals 31 and 33 by means of a cable 35. Terminals 32 and 34 are connected to target electrodes 14 and 12, respectively, and terminals 33 and 31 are connected to target electrodes 13 and 15, respectively. Connected between terminals 32 and 34 is a resistor 38 and connected between terminals 33 and 31 is a resistor 37. Resistors 37 and 38 perform a dual function. They act to maintain the potential difference across the electrodes of the targets due to the voltage drop across them, and they also serve to afford a completed circuit for test purposes in a manner which will be explained hereinafter.

The secondary winding 40 of transformer T2 has one end thereof connected to the control electrode 42 of a gaseous discharge tube V2. The other end of primary winding 40 is connected to a terminal 46 to which is also connected the cathode 44 of tube V2. Thus in effect, secondary winding 40 is connected between the control electrode and cathode of the gaseous discharge tube V2. In like manner, secondary winding 41 of transformer T1 is conected between the control electrode 43 of a gaseous discharge tube V1 and the terminal 47 to which is connected the cathode 45 of the tube V1. Terminals 46 and 47 are connected together through biasing resistor 48, junction and biasing resistor 49.

Junction 50 is connected to ground (the chassis of the control unit) through lead 51. The function of biasing resistors 48 and 49 will be explained hereinafter. The anode 52 of discharge tube V2 is connected to the positive side of power supply source 18 through leads 54, 56, junction 57, switch 58, junction 59 and lead 69. The anode 53 of discharge tube V1 is connected to the positive side of the power supply source 18 through lead 55, junction 57, switch 58, junction 59 and lead 69. It will be seen from this connection that the positive voltage of the power supply source will be applied to the anodes of tubes V1 and V2, and when the system is in the static or unoperating condition the control electrodes and cathodes of tubes V1 and V2 will be at ground potential. Junction 46 is connected through a coupling capacitor 62 to junction point 64 and thence to control electrode 66 of a gaseous discharge tube V4. In like manner, junction 47 is connected through a coupling capacitor 63 to junction and thence to the control electrode 67 of a gaseous discharge tube V3. The cathode 68 of tube V4 and the cathode 69 of tube V3 are connected together through junction 70, and junction 70 is connected to ground through a resistor 71, the function of which will be explained hereinafter. Anode 72 of tube V4 is connected to lead 54 at terminal 74, and anode 73 of tube V3 is connected to lead 55 at junction 57. Thus, the voltage of the power supply source is applied to the anodes of tubes V3 and V4 as it is to the anodes of tubes V1 and V2. A positive bias voltage of approximately 70 volts is applied to control electrodes 66 and 67 of tubes V4 and V3 respectively through lead 76 which is connected to the voltage divider at the junction 75, junction 77, resistors 78 and 79 and junctions 64 and 65.

When switch 58 is closed the voltage of power supply source 18 is applied to the anodes of tubes V1, V2, V3 and V4. Inthe embodiment shown this voltage is approximately volts, however, it is to be understood that a different voltage might be used depending upon the components used in the circuit. The cathodes and control electrodes of tubes V1 and V2 will be at ground potential, and the control electrodes 66 and 67 of tubes V4 and V3 respectively will be at a positive potential of approximately 70 volts. The cathodes of tubes V4 and V3 will be at ground potential.

In operation, after the signal has been given to draw and fire, assume for purposes of illustration that target 10 has been struck first. When this occurs the electrodes 12 and 14 of target 10 will be short-circuited momentarily as the projectile passes through the target and the charge on these electrodes will be dissipated resulting in a high frequency transient pulse which will be substan tially attenuated in the leads 36, and will have no effect upon the indicating circuit. However, after the elec trodes 12 and 14 have been discharged the power supply source 18 and the voltage divider will start to charge the electrodes. This charging current passes through primary 24 of transformer T2 in the form of a relatively low frequency transient pulse. This transient pulse in the primary 24 of transformer T2 will result in a large positive voltage pulse in the secondary 40 which will be applied to control electrode 42 of tube V2 igniting the tube. When V2 fires, junction point 46 will rise from ground potential to approximately a plus 25 volts, due to the passage of current through resistor 48. This positive 25 volts is applied to the control electrode 66 of tube V4 through coupling capacitor 62 and junction 64, and is added to the 70 volts bias on the control electrode. In the embodiment here shown the 70 volts bias on the control electrodes of tubes V3 and V4 is not sufficient to fire the tubes, it requiring approximately a 90 volt bias to initiate gaseous discharge. Thus, when the 25 volts has been added to the 70 volts on the control electrode 66 of tube V4 it will be a sufficient bias to initiate discharge and tube V4 will fire. When tube V4 fires juncflair 70 will rise in potential from ground etenaar to approximately 25 volts due to the passage of current through resistor 71, thus causing a: rise in potential of cathode 69 of tube V3. This increase in potential of cathode 69 of tube V3 has the effect of decreasing the bias on the control electrode 67 from 70 volts to approximatel 45 volts. 7 o M Assuming now a hit on target 11, electrodes 13 and 15 of target 11 will be' discharged andthen will commence to charge again aswas the case with target 10. The charging current in'" primary 25 or transformer T1 will cause a large positive voltage pulse in the secondary 41 which will be applied to the control electrode 43 of tube V1. This positive voltage pulse on control electrode 43 will be sufiicient to initiate discharge of tube V1, and junction 47 will rise in potential to approximately 25 volts due to the passage of current through resistor 49. This 25 volt riseis applied through coupling condenser 63: to junction 65 and thence to control electrode 67 of tube V3. However, tube V3 will not fire inasmuch as the 25 volts added to the previously decreased bias on tube V3 will result in a voltage on the control electrode 67 of only 70 volts with respect to the cathode 69, which is' not su'fiicient to fire tube V3. It can be seen from thevforegoing' that both.of.the contestants struck their targets and tubes V1 and V2 both fired atto'rding' an indication of the accuracy, of the contestants. Thus, the first stage ,of'theindicator circuit which comprises tubes V1 and V2 might well be called the hit stage. Since target was struck before target 11 tube V4 was fired affording an indicationof this fact and tube V3 remained dark, thereby giving an indication that target 10 was struck first. For this reason the second stage of the indicatorcircuit comprising tubes V3 and V4 might be called the winner stage.

It has beenfoundin practice that when a hit is made uponpne target, before a hit is made on the remaining targets, the discharge of that target will tend to discharge the other targets also. To obviate this diificulty, a condenser 80 is connected between lead 22 and ground, or, eifectively,.between the midpoint of the primaries 24 and 25 and ground. Condenser 80 acts to maintain a stable D1 C potential. across the target electrodes 12, 14 and 13, 15. In addition, condenser 80 reduces the A. C. impedance of the voltage divider so that the charging current; will be a maximum. I I

After the course of fire has been completed, and the results noted, switch 58 is momentarily openedto remove the anode voltage on tubes V1 V2, V3 and V4, thus extinguishing those tubes' which are fired. Subsequent closing of switch 58 will then place the indicator circuit mec anism for the next course of fire, Inasmuch as switch 58 is in series between the anodes of the tubes and the power, supply, but is not in circuit with the targets; there will be no change in the charge on the targets by the actuation of switch 58 I V p A rhilliarnmeter 81 is placed in series with the voltage divider, ,and is used to enable the operator to make a rapid check from time to time as to the proper condition of the indicator. ,Thus,.when the indicator is in proper working. order, the rnilliammeter will register a fixed valueof current, such as, for example, 0.5 milliampere. If there is a short circuit in the targets or in the target leads; the milliammeter will read something lessthan its proper reading of 0.5 milliampere, and an open circuit in the target leads will causethe milliammeter to read a value higher than the value 0.5 milliampere. H

T he embodiment of my invention shown in' Fig. 2 utilizes neon lamps instead of cold cathode gaseou's discharge tubes, and makes use of the fact that while these lamps require a potential difference of approirimately 75 volts between their electrodes to cause them' to fire they maintain a potential diiference of approximately 52 volts between' their electrodes after they have been fired. The targets used in the embodiment of Fig. 2 are the same as those' used inthe embodiment shawl; in" Fig. 1 Thus, target 102' comprises electrodes 1'04' and 106' Separated by a dielectric material 108 andtarget 1 01 com; prises electrodes 103 and separated by a dielectric material 107. The power supply source 109 maybe any suitable source of D. C. potential. In theembodimefit shown I utilize a battery having a maximum voltage output of 67.5 volts. A voltage divider comprising r'esistances 110 and 111 is connected across thepower supply. A portion of the voltage across the voltage" divider is fed through lead 112' to terminal 113. One endof tl ie primary 114 of a transformer T4 and one end of the primary 115 of a transformer T3 are likewise connected to terminal 113. The other end of the primary 114 is connected'to a terminal 116 and the other end of pri'r'nary 115 is connected to a terminal 117. The negative side of battery 109 is connected through lead 118 to ground and thence to terminals 110 and 120 of the target circuit. Terminals 116 and 120 are connected to terminals 122 and 124 of the target by mean s of a'cable 126 which may be any standard cable, such as a twisted pair or the like. In a like manner, terminals 117 and 1 19 areconnected respectively to terminals and 123 by means of cable 127. Connected across terminals 122 and 124 is a resistor 128 and connected across terminals 123 and 125 is a resistor 129. Resistors 128 and 129' perform the same functions as the resistors 37 and 38 of the embodiment shown in Fig. 1, that is they act to maintain the potential difierence across the electrodes of the targets du'eto the voltage drop across them, and they also serve to afford a completed circuit for test purposes.

One end of the secondary 130 of transformer T4 connected to one electrode 132 of a" neon lamp L2, and in like manner one end of secondary 131 of transformer T3 is connected to one electrode 133' of a ndn' a'mp' L1.

The other end of secondary 130 is connecte to the positive side of the power supply source through a resistor 134, lead 135, junction 136', switch 137 and junction 138 In like manner, the other endof secondary 13 1 of transformer T3 is connected to the positive side of the power supply source 1159 through resistor 139, lead 135, j'unotion 136, switch 137 and junction 1 38. The other electrode 14a of lamp LZ and the electrode 141 of lampLl are connected together and to ground through junction 144, lead 142 and junction 143. p A

Eiectrode 132 of lamp L2 is connectedto an electrode 146 of a neon lamp L4 througha coupling condenser 14% Electrode 133 of lamp L1 is connected to an electrode 145 of a neon lamp L3 throug'h1a coupling condenser 14-7. Connected between electrode 146 of lamp L4 and junction 143 which is connected to ground is a resistor150, and in like manner a resistor 149 is connected between electrode 145 of lamp L3 junction 14 3 The other electrode 152 of lamp L4 is connected to the positivesig'ie of the power supplysource 109; through junction 153, resistor 154, lead 155, junction136, switch 137 and junction 138. The other electrode 151 of lamp L3 is also connected to the positive side' of. the power supply sourcethrough junction 153, resistor 154, lead 155, junction 13 5, switch 137 and junction 13%. v p

Under static conditions when the system is ready to operate but prior to any target being struck by' a projectile, switch 137is closed and electrodes'132 of IampLZ and 133 of lamp L1 will have a positive potential of 67 /2 volts impressed on' them, while electrodes of lamp L2 and 141 of lamp L1 will be at ground potential. Electrodes 151 and 152 of lamps L3 and L4 respectively will have a positive voltage of 67 /2 volts while electrodes and 146 of lamps L3 and L4 respectively will be at ground potential. in order to prevent accidental firing of any of the lamps due to a momentary transient surge upon closing of switch 137, resistor 156- is connected across the secondary 130 of transformer T4 and resistor 157 is connected across the secondary 131 of transformer 7 T3. Resistors 156 and 157 act to attenuate any transient surge and thus prevent accidental firing of the tubes.

Assume now that the signal has been given to draw and fire, and that a bullet has struck target St l -2. The charge on the plates of target 102 will be neutralized, thus causing a high frequency transient pulse which is attenuated in cable 126. The power supply source and voltage divider will then supply a low frequency charging pulse through lead 112 and junction 113 and primary 114 to the plates of target 102. When this occurs a positive voltage pulse appears in secondary 130 of transformer T which is sufficient magnitude when added to the 67 /2 volts bias across electrodes 132 and 146 of lamp L2 to cause lamp L2 to fire. Inasmuch as the regulating voltage of lamp L2 is approximately 52 volts, the voltage across the electrodes 132 and 140 will drop from 67 /2 volts to 52 volts, which causes a negative voltage of 15.5 volts to appear across resistor 150. This has the effect of reducing the potential of electrode 146 of lamp L4 from ground to minus 15 /2 volts, thus placing a potential difference between electrodes 146 and 152 of approximately 83 volts, causing lamp L4 to fire. When lamp L4 fires the potential immediately drops to approximately 52 volts between the electrodes 146 and 152. If resistors 149 and 156 are selected to be approximately identical and are of. approximately 15 the value of resistor 154, it will be seen that, inasmuch as electrode 152 of lamp L4 is connected to electrode 151. of lamp L3 at junction 153 and electrode 146 of lamp L4 is connected to electrode 453 of lamp L3 through resistor 150, junction 143 and resistor, hi9 with junction 143 being at ground potential, the potential difference between electrodes 145 and 151 of lamp L3 will drop to approximately 54 volts when lamp L4 is fired, the voltage drop across resistor 150 being negligible with re spect to the drop across 154.

Assuming now a hit on target 101, the discharge and charging cycle of the plates will be the same as for target 102 when it was struck and a positive voltage pulse will appear on secondary 131 of transformer T3. This positive voltage pulse will be sufficient to fire lamp L1. The potential difference across electrodes 133 and 141 of lamp L1 will then drop to the regulating voltage of approximately 52 volts causing a negative signal to appear across resistor 149 of approximately /2 volts. This negative signal of 15 /2 volts effectively reduces the potential on electrode 145 of lamp L3 by 15 /2 volts, but inasmuch as the potential difference between electrodes 145 and 151 of lamp L3 had dropped to 54 volts upon the firing of lamp L4, the 15 /2 volts across resistor 14? will act to increase the potential difference between electrodes 145 and 151 to 69 /1 volts, which is not sufficient to fire lamp L3. The condition which now prevails is lamp L1 and lamp L2 are both glowing, as is lamp L4, but lamp L3 remains dark. Thus, the first stage of the indicator circuit comprising lamps L1 and lamps L2 might be called the hit" stage, inasmuch as lamps L1 and lamps L2 will afford an indication whenever their associated targets are struck. The second stage of the indicator circuit comprising lamps L3 and L4 is the winner stage inasmuch as the only lamp in that stage which will glow and thus afford an indication of a hit is the lamp, the associated target of which was struck first. Capacitor 158 is connected across a portion of the voltage divider and thus effectively across the electrodes of the targets and acts to maintain a stable D. C. potential across the target electrodes and to reduce the A. C. im pedance of the voltage divider in manner similar to that described in connection with condenser 84 of the Fig. l embodiment.

Milliammeter 159 is connected in circuit with the voltage divider and power supply source and functions in the same manner as milliammeter 81 of Fig. l to afford an indication. of the proper working conditions of the circuit.

One important feature of such arrangements as hereinbefore explained is the fact that I do not utilize my targets as a simple series switch, as in the prior art, and, consequently, the D. C. resistance of the targets is not important to proper operation. Exceedingly wide variations in this resistance due to dampness, heat, dielectric aging effects, etc. will not affect either the operation or the accuracy of the system.

Another important feature of my invention is that, by using a low frequency charging pulse, the problem of attenuation of the electrical signal due to travel from the target to the indicator is non-existent, and accurate results have been obtained even when the targets have been separated from the indicator by distances greater than mile. Since ordinary twisted pair cable may be used, this obviously represents a great saving in equipment expense.

While I have shown and described my invention as used in a dueling course of fire system, it having particular utility in such an arrangement, it is obvious that an indicating system involving any number or combination of targets may be had by utilizing the necessary number of targets and circuit components associated therewith.

What I claim is:

l. A target shooting apparatus comprising, a plurality of targets, a plurality of indicator circuits of the same number as there are targets, there being an indicator circnit associated with each target, said indicator circuits being adapted to be connected to a source of electrical power for generating a signal when a target is struck by a projectile, each of said indicator circuits having a first stage responsive to the signal generated when its associated target is struck for indicating when said target has been struck, each of said indicator circuits having a second stage responsive to actuation of the associated first stage for indicating when its respective target has been struck first, and means interconnecting the plurality of indicating circuits whereby the response of the second stage of any given circuit when its target has been hit first causes the second stages of the other circuits to become ineffective to indicate a first hit, the first stage associated with each of said targets remaining actuable in response to a signal generated by a hit on its respective target after another target has been struck first.

2. A target shooting apparatus comprising, a plurality of targets, a plurality of indicator circuits of the same number as there are targets, there being an indicator circuit associated with each of said targets, said circuits being adapted to be connected to a source of electrical power for generating a signal when a target is struck by a projectile, each of said indicator circuits having a first stage responsive to the signal generated when its associated target is struck for indicating when said target has been struck, and a second stage responsive to actuation of the associated first stage, and means interconnecting the plurality of indicator circuits whereby each of said second stages is adapted to prevent actuation of the other of said second stages when its associated target has been struck first, the first stage of each of said targets remainmg actuable in response to a signal generated by a hit on its respective target after another target has been struck first.

3. A target shooting apparatus comprising a plurality of targets, a plurality of indicator circuits of the same number as there are targets, there being an indicator circuit associated with each of said targets, means including a transformer having a primary winding connected to each of said targets for generating a signal when said target is struck by a projectile, each of said indicator circuits having a first stage responsive to the signal generated when its associated target is struck for indicating when said target has been struck, each of said first stages having a gaseous discharge tube connected to the secondary winding of the transformer, the primary of which is connected to its associated target, each of said indicator circuits having a second stage responsive to actuation of the associated first stage for indicating when its respecswim-=24 tivgtiitget is the rst target'hi't'ofthe plura'lity o f'targets, each at said econd stages including a gaseous tiis'chatge tube connected to the gaseous discharge'tiibe of the associated first stage in a' main-cits be actuated by passage of current through said g a s 'eou sdi schaig tube of Said first Stage, and nieans interconnectingthe plural'ity of' di' cator circuits whereby the response of the second stage of any given circuit when its arget has beenfi'rst hit of the plurality of targets causes the second stages of the other circuits ts become ineffecti e to indicate at firs hit, the first stage associated with each of said targets remaining actuable in response t ti signal" generated by a hit on its respective target" after another target has been hitfiis t. A

4. A target shooting appaira t'us' as claimed in 3, wherein the means for generating a" signal ct'jmprises a battery connected in series with each of said target's. V A target shooting apparatus as cl'ainied in claim wherein each of the gaseous discharge tubes" of said indicatorcircuits has a cathode, anode and control electrode, the control electrode of each of the gaseous discharge tubes of said first stages being connected to the secondary winding of said transformer. c 6'. A target shooting apparatus as claimedinclaim 3, wherein each of thegaseo'usdis'charge tubeset said indicator circuits has two electfodes', one electrodeot the gaseous discharge tube of each of said first indicator stages'being connected to the secondary of said transtotmer and the other electrode being connected to ro nd;

7. A target shooting apparatus comprising plurality of targets, an indicatorcir cuit' connected toeach of said targets, each of said indicator circuits comprising a first electro -s'ensitive indicator means" responsive toa hit on itsj respective target, each indicator circuit comprising a second electro-sensitive indicator rri e'ans' responsivewh'en its; respective target has been the first target hit of said plurality of targets, and means' interconnecting the indicator circuits for rendering ineffective thesecdnd electrosensitive indicator means at the other circuits when the circuit of an one of said second electr for mass has responded to a first targ'e specti've target, the first electro sensitiye H l A or each target not hitfi'rst re iaiiiiiig actuahl 111 es on e to a hit on its respective target a'tti aiib' 'i target has been hit first. c

8. K target s ooting appar'atusLconipris ottai'gets; an indicator c t'ciiit' connected t M tar ets, each of said indica or" circuits comprising" iij ist edectfori tube means responsive" to alhi t on its" respective target, each indicator circuit comprising" a seco tion' tube responsive its respective target has been the first target hit means iiite csiiiieet" I k p p for tendering iii'eirective the second erection mire means of the other circuits when the circuit of any one of's'aid second electron tube means has resppndedto a first target hit on its respective target, the first electr tuh'e means associated with each of said targets rern'aining actuable in response to a hit on its respective target after another target has'beerihit first. H '9! A f 15 9??? eeetawf v gm ri ap ut l t o f t argets'g an indicator circuit connected to each of said targets, each of said ind t or circuits comprising a first electron tube means responsive to on its rcspective t e isin a con lecfr ,6 me e' ...l i sa j 9 .1 is a d. fi c t qnmb m a t) $35 9. 1. i 39 1 ina e n i j l ei n e ct o W 2 me s9 I 9,rssrzesttresficuit wh y, ,a. hi on the target of the respective circuit will cause transmission of a signal from the first electron tube means to the second electron tube means of the respective circuit, said signal being eflfective to change the energization state of said second electron tube means when its respective target has been the first target hit of a plurality of targets,

and means interconnecting the respective indicator circuits tor rendering ineffective the second electron tube means of the other circuits to indicate a first hit when the circuit of any one of said second electron tube inearis has responded to a first hit on its respective target, the first electron tube means associated with each of said targets remaining actuable in response to a hit on its respective target after another target has been struck first.

I 101' A target shooting apparatus comprising a plurality of targets, means for applying an electric charge across spacedportions of each target, passage of a projectile through any target being effective to equalize the charge on the spaced portions of the respective target, an indi cator circuit connected to each target, a first electron tube means connected in each indicator circuit, means for applying a signal to said fi'rstelectron tube means of each circuit when the target of the respective circuit becdn'ie's recharged subsequent to" the passage o'f a projectilc through the respective target, a second electron tube means" connected in each circuit, means couplingsaid first and second electron tube means of each circuit, said coupling means being eifective to transmit a signal from said first electron tube means to said second electron'tube means upon the occurrence of a hit on the target of the respectivecir'cuit and means interconnecting the plurality of circuits with each other so that only the second electron tube means of the circuit Whose target is first hit is eifec'tive to indicate a first hit, the first electron tube means associated vvith each of said targets remaining actuable in response to a hit on its respective target after another target has been struck first.

11. A target shooting apparatus" comprising a plurality of targets, as indicator circuit connected to cach t said targets, each of said indicator circuits comprising a first gaseous discharge tube means, means for changing the potential applied to said first gaseous discharge tube means to render saidfi'rst gaseous discharge tube means conductive upon the occurrence of a hit on its respective target; each indicating circuit comprising a second gas: e'o'us discharge" tube means for indicating when its res'pec'tiv'e target is the first target hit of said pluralityof targets; means coupling said" first ands'econd tube rneans breach" circuit to each othe said cou ling means being effective to transmit a' signal from" said first tube iiie'ans to'said second tube means upon said first tube means heciiiitig conductive due to a hit on its respe tive target, and means interconnecting the plurality of indicator circuits so that only the second gaseous discharge tube means of the circuit Whose targetis first hit is effective to indicate a first hit, said interconnecting nieans' rendering' inefiective' the second gaseous discharge tube means of the circuits Whose targets" are not first hit, the firist gaseous discharge tube means of each of said targets remaining actuabie response to a hit on its respective target'tafter another target has been hit first.

' 12. A targetshooting apparatus comprising a plurality of targets, an indicator circuit connected to each at said targets, each of said'. indicator circuits comprising a first gaseous discharge tub'e'means having a cathode, an anode and a control grid, means for applying a signal voltage to the control grid of said first gaseous discharge tube of each' circuit to cause conduction of said first tube when the target of said' respective indicator circuit is hit, each indicator circuit coin ising a second gaseous discharge tiibc havin'g a cathode, an anode and a control g'rid', ni ing the first, gaseousdischarge tube of each indicator ci'r'cuit' to th 'on'trol grid: of its corresponding second gaseousdischa'rge' tube, means interconnecting the second gaseous discharge tubes of the plurality of circuits, conduction of the first gaseous discharge tube of the circuit Whose target is the first hit of said plurality of targets being effective to trigger the conduction of the second gaseous discharge tube of said circuit whose target was first hit, conduction of said second gaseous discharge tube being effective to bias the second gaseous discharge tubes of the other circuits against conduction despite conduction of the first gaseous discharge tubes of said other circuits, the first gaseous discharge tube means of each of said targets remaining actuable in response to a hit on its respective target after another target has been hit first.

13. A target shooting apparatus comprising a target, means for applying an electric charge across spaced portions of said target, passage of a projectile through said target being effective to equalize the charge on said spaced portions, an indicator circuit connected to said target, a first electron tube means connected in said indicator circuit, means for applying a signal to said first electron tube means upon the recharge of said target subsequent to the passage of a projectile through said target, a second electron tube means connected in said circuit for indicating when said target is the first target hit of a plurality of targets, means coupling said first electron tube means to said second electron tube means, said coupling means being effective to transmit a signal from said first electron tube means to said second electron tube means upon the occurrence of a hit on said target, said second electron tube means being actuable to indicate a first hit only when said target has been hit first, said first electron tube means remaining actuable in response to a hit after another target has been hit first.

14. A target shooting apparatus comprising a target, means for applying an electric charge across spaced portions of said target, passage of a projectile through said target being effective to equalize the charge on said spaced portions, an indicator circuit connected to said target, a first electron tube means connected in said indicator circuit, means for applying a signal to said first electron tube means upon the recharge of said target subsequent to the passage of a projectile through said target, a second electron tube means connected in said circuit for indicating when said target is the first target hit of a plurality of targets, means coupling said first electron tube means to said second electron tube means, said coupling means being effective to transmit a signal from said first electron tube means to said second electron tube means upon the occurrence of a hit on said target, and biasing means connected to said second electron tube means for rendering said second electron tube means ineffective to indicate a first hit when said target is not the first target hit of a plurality of targets, said first electron tube means remaining actuable to indicate a hit on said target after another target has been hit first.

15. A target shooting apparatus comprising a target, an indicator circuit connected to said target, said indicator circuit comprising a first electron tube means for indicating when said target has been hit, said circuit comprising a second electron tube means for indicating when said target has been the first target hit of a plurality of targets, means coupling said first tube means to said second tube means, means for applying a first signal to said first tube means to change the energization characteristic of said first tube means when said target has been hit, said change in the energization characteristic of said first tube means upon the occurrence of a hit causing a second signal to be transmitted to said second tube means through said coupling means, said second signal being effective to change the energization state of said second tube means only when said target has been the first target hit of a plurality of targets, said first electron tube means remaining actuable to indicate a hit on said target after another target has been struck first.

16. A target shooting apparatus comprising a target, an indicator circuit connected to said target, said indicator circuit comprising a first gaseous discharge tube means for indicating when said target has been hit, said circuit comprising a second gaseous discharge tube means for indicating when said target has been the first target hit of a plurality of targets, means coupling said first tube means to said second tube means, means for applying a first signal to said first tube means to change the energization state of said first tube means when said target has been hit, said change in the energization state of said first tube means causing a second signal to be transmitted to said second tube means through said coupling means, said second signal being efiective to change the energization state of said second tube means only when said target has been the first target hit of a plurality of targets, said first gaseous discharge tube means remaining actuable to indicate a hit on said target after another target has been hit first.

17. A target shooting apparatus comprising in combination, a target, means for applying a potential difference across a portion of said target traversed by a projectile, an indicator circuit connected to said target, said indicator circuit comprising a first gaseous discharge tube means for indicating when said target has been hit by a projectile, means for rendering said first gaseous discharge tube means conductive upon the passage of a projectile through said target, a second gaseous discharge tube means for indicating when said target has been the first target hit of a plurality of targets, means coupling said first gaseous discharge tube means to said second gaseous discharge tube means, said coupling means being effective to communicate a signal from said first gaseous discharge tube means to said second gaseous discharge tube means when said first gaseous discharge tube means becomes conductive, said first gaseous discharge means remaining effective to indicate a hit on said target after another target has been struck first.

18. A target shooting apparatus comprising a plurality of targets, a separate indicator circuit connected to each of said targets, each of said indicator circuits comprising a first gaseous discharge tube means responsive to a hit on its respective target, each indicator circuit comprising a second gaseous discharge tube means respon' sive when its respective target has been the first target hit of said plurality of targets, means interconnecting the respective indicator circuits with each other for rendering ineffective to indicate a first hit the second gaseous discharge tube means of the circuits whose respective targets have not been first hit when any one of said second gaseous discharge tube means has responded due to its respective target being the first target hit, the first gaseous discharge tube means associated with each of said targets remaining actuable in response to a hit on its respective target after another target has been hit first.

References Cited in the file of this patent UNITED STATES PATENTS 474,109 Vogel May 3, 1892 1,286,491 Baker Dec. 3, 1918 1,906,260 Gibbs May 2, 1933 2,181,948 McClellan Dec. 5, 1939 2,185,628 Daum Jan. 2, 1940 2,241,135 Jaimet May 6, 1941 2,309,614 Jensen Jan. 26, 1943 2,536,744 Henry Ian. 2, 1951 2,576,960 McAvoy Dec. 4, 1951 2,629,598 Hooker Feb. 24, 1953 

